2014 Fiscal Year Research-status Report
Prepation of Generic Oxides Melt Model for Late-Phase Severe Accident Analysis
| Project/Area Number |
26630484
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| Research Institution | Nagaoka University of Technology |
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Principal Investigator |
DO T.M.Dung 長岡技術科学大学, 工学(系)研究科(研究院), 助教 (90638420)
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| Co-Investigator(Kenkyū-buntansha) |
小川 徹 長岡技術科学大学, 工学(系)研究科(研究院), 教授 (10354672)
SUJATANOND Supam 長岡技術科学大学, 工学(系)研究科(研究院), 助教 (80726208) [Withdrawn]
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| Project Period (FY) |
2014-04-01 – 2017-03-31
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| Keywords | Cs2MoO4 / vaporization / deposition / cesium polymolybdate / thermodynamics / severe accident / MoO3/Cs2O / Cs2O-MoO4 |
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| Outline of Annual Research Achievements |
Vaporization and deposition of Cs2MoO4 had been tested at different temperature up to 1300 degree C, in different atmosphere conditions on Au, Pt and SUS304.
The results showed that, in dry Ar gas, at temperature higher than 1500 K, Cs2MoO4 reacted with Cr, forming Cr2O3, Cs2O(g) and Mo metal, while the deposit on Pt was Cs2MoO4. (Fall Meetings 2014 of Atomic Energy Society of Japan).
The deposit had changed in humid condition. At the tempearurtes higher than 1500 K, a thin layer of Mo oxide was found on SUS304 surface. Mo oxide also was found in the cross-section of SUS304. It is concluded that when the steam oxidation of SUS and the deposition of Cs2MoO4 proceed simultaneously, Cs and Mo are incorporated into the oxides scale of SUS304. At the temperatures lower than 1500 K, the MoO2 crystals covered the SUS surface. However, the deposit was Cs2MoO4 at the temperatures lower than 730 K in both dry and humid condition.
The K-edge XANES of Cs2MoO4, Cs2Mo2O7, Cs2Mo3O10 and Cs2Mo4O13 were also obtained to ascertain the XANES features as a function of the MoO3/Cs2O ratio. The XANES feature of Cs2MoO4 did not change appreciably at melting. The entropy of fusion of the Cs2MoO4 was also very small, reflecting this little change in the structural features. These characteristics were considered in making the thermochemical model of the Cs2O-MoO4 system.(Spring Meeting 2015 of Atomic Energy Society of Japan).
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
Now we have clarified how the stability of Cs2MoO4 is affected in various environments, and almost finished thermochemical modeling of the Cs2O-MoO4 system. Besides, we can synthesize all Cs2O-MoO3 compounds with good quality.
Therefore, we are sure that we can produce a sound basis for the MCCI analysis with the extension of the ideal mixing of complex components (IMCC) model.
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| Strategy for Future Research Activity |
The study on the vaporization and deposition of Cs2Mo2O7 will be continued at different conditions, by thermogravimetry and transpiration techniques.
Based on the vaporization behavior of Cs2MoO4 and Cs2Mo2O7, the interaction of cesium polymolybdate and the vapor species from vaporization of zircaloy and basalt-concrete will be conducted in both dry and humid conditions in different environment condition by transpriation test.
The results will be used for improving the thermochemical model of Cs-Mo-O, which we have made in FY2014, and extending to the thermochemical model of (Zr-Fe-O)+(Cs-Mo-O) system, for completing the ideal mixing of complex-components.
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| Causes of Carryover |
Due to the late calculation during buying materials, the payment of FY 2014 was transfered the payment of the FY 2015.
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| Expenditure Plan for Carryover Budget |
The amount of money left will be used to buy materials for experiment of FY 2014.
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